Aluminum titanate (Al.sub.2 TiO.sub.5) ceramic is suitable for use as an insulative coating for metals, for applications where junctures between two materials of widely different thermal expansion coefficients are encountered and in applications such as catalyst supports where porous structures having good thermal shock properties are needed. It exhibits a unique combination of a high melting point (1860.degree. C.), and low coefficient of thermal expansion (0.5.times.10.sup.-6 /.degree.C. over a temperature range of 20.degree. C. to 1000.degree. C.).
The traditional method for preparing aluminum titanate is to mix Al.sub.2 O.sub.3 and TiO.sub.2 and heat to a temperature of 1300.degree. to 1400.degree. C. Other methods for preparing aluminum titanate have also been described. For example, U.S. Pat. No. 3,825,653 describes a method for preparing a sinterable aluminum titanate powder by (1) coprecipitating halides or alkoxides of aluminum and titanium as a solid hydroxide, (2) drying the resulting hydrated aluminum titanium hydroxide and (3) calcining in air at 700.degree.-800.degree. C. In The Science and Engineering Review of Doshisha University, 22 (1), April 1981, p. 26, Yamaguchi et al. describe the preparation of .beta.-aluminum titanate at a temperature of 1320.degree. C. using a mixture of .alpha.-Al.sub.2 O.sub.3 and TiO.sub.2 powders. The powder mixture was obtained by the simultaneous hydrolysis of aluminum and titanium alkoxides to give an equimolar mixture of the amorphous oxides.